• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
EnvironmentNuclear Energy

Microsoft strikes deal to reopen Three Mile Island, site of the worst nuclear accident in U.S. history, to power its AI data centers

By
Chris Morris
Chris Morris
Former Contributing Writer
Down Arrow Button Icon
By
Chris Morris
Chris Morris
Former Contributing Writer
Down Arrow Button Icon
September 20, 2024, 11:08 AM ET
Three Mile Island is reopening after being dormant for five years.
Three Mile Island is reopening after being dormant for five years. Jeff Fusco—Getty Images

Three Mile Island, the site of the worst nuclear accident in U.S. history, is opening up once again.

Microsoft and Constellation Energy, which owns the plant, have struck a deal that will see the plant’s undamaged reactor resume operations to power Microsoft’s AI data centers. Microsoft has signed a 20-year power-purchase agreement with Constellation, which will spend $1.6 billion to restart the reactor. It’s expected to be operational again by 2028.

Constellation shares were up 14% in early trading Friday morning.

“Before it was prematurely shuttered due to poor economics, this plant was among the safest and most reliable nuclear plants on the grid, and we look forward to bringing it back with a new name and a renewed mission to serve as an economic engine for Pennsylvania,” said Joe Dominguez, president and CEO of Constellation in a statement.

Read more: I loved my job at Microsoft, but I had to resign on principle. Here’s why

The facility’s Unit 1 reactor will be restarted. That facility sits next to the Unit 2 reactor that had the partial meltdown in 1979. Unit 1 “permanently shut down” on Sept. 20, 2019 after starting operations in 1974. Constellation purchased the unit in 2000, and it produced enough electricity in the following years to power 800,000 homes for almost two years and “offset more than 95 million metric tons of carbon, the equivalent of nearly 20 million cars off the road,” the company says.

Constellation was not the owner of the Unit 2 reactor.

The owners of approximately one-third of the country’s nuclear power plants are reportedly taking with companies to help power data centers. And a big source of that demand is the growing use of artificial intelligence. That’s raising concerns about the impact on the larger power grid, which has struggled some as the country experiences extreme weather conditions. (The grid is also considered a high-risk target of hackers.)

Experts have warned data centers could become a big strain on the U.S. power grid, with the nine-year projected growth forecast for North America essentially doubling from where it stood a year ago. Last year, the five-year forecast from Grid Strategies projected growth of 2.6%. That number has since nearly doubled to 4.7%—and planners expect peak demand to grow by 38 gigawatts. In real-world terms, that’s sufficient to power 12.7 million homes.

“The U.S. electric grid is not prepared for significant load growth,” Grid Strategies warned.

The Fortune 500 Innovation Forum will convene Fortune 500 executives, U.S. policy officials, top founders, and thought leaders to help define what’s next for the American economy, Nov. 16-17 in Detroit. Apply here.
About the Author
By Chris MorrisFormer Contributing Writer

Chris Morris is a former contributing writer at Fortune, covering everything from general business news to the video game and theme park industries.

See full bioRight Arrow Button Icon

Latest in Environment

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Environment

iran
EnergyFood and drink
A global food emergency: Why the closed Strait of Hormuz puts half the world’s calories at risk
By Aya S. Chacar and The ConversationApril 9, 2026
1 hour ago
xi jinping
EnergyChina
Deutsche Bank says China is energy ‘winner’ in age of war
By Ishika Mookerjee and BloombergApril 9, 2026
3 hours ago
sheinbaum
EnergyMexico
Claudia Sheinbaum wants Mexico to start fracking to get away from Trump’s natural gas. But she won’t call it that
By María Verza and The Associated PressApril 9, 2026
4 hours ago
data centers
EnergyData centers
Data centers are destroying states’ clean energy dreams
By Jessica Hill and The Associated PressApril 9, 2026
5 hours ago
heat
Environmentclimate change
U.S. just had its hottest March ever, in records dating back 132 years
By Seth Borenstein and The Associated PressApril 9, 2026
5 hours ago
The U.S. just had its hottest March in 132 years. Scientists say to buckle up for the rest of the year
EnvironmentWeather and forecasting
The U.S. just had its hottest March in 132 years. Scientists say to buckle up for the rest of the year
By Seth Borenstein and The Associated PressApril 8, 2026
1 day ago

Most Popular

The U.S. had a national debt ‘home run’ in its grasp, says Jamie Dimon. But the government did nothing, and now its best option is crisis management
Economy
The U.S. had a national debt ‘home run’ in its grasp, says Jamie Dimon. But the government did nothing, and now its best option is crisis management
By Fortune EditorsApril 8, 2026
1 day ago
U.S. government is spending $88 billion a month in interest on national debt—equal to spending on defense and education combined
Economy
U.S. government is spending $88 billion a month in interest on national debt—equal to spending on defense and education combined
By Fortune EditorsApril 9, 2026
7 hours ago
Self-made billionaire MrBeast says his work-life balance is nonexistent and calls it a ‘miracle’ if he works less than 15-hour days: ‘I live to work’
Success
Self-made billionaire MrBeast says his work-life balance is nonexistent and calls it a ‘miracle’ if he works less than 15-hour days: ‘I live to work’
By Fortune EditorsApril 8, 2026
1 day ago
2 years ago, Saudi Arabia quietly canceled the ‘petrodollar’ deal with America that wired the world economy for 50 years. Then war broke out in Iran
Energy
2 years ago, Saudi Arabia quietly canceled the ‘petrodollar’ deal with America that wired the world economy for 50 years. Then war broke out in Iran
By Fortune EditorsApril 7, 2026
2 days ago
MacKenzie Scott's latest donation takes her HBCU giving to well over $1 billion
Success
MacKenzie Scott's latest donation takes her HBCU giving to well over $1 billion
By Fortune EditorsApril 7, 2026
2 days ago
Artemis II’s astronauts are on their way home—a six-figure salary but no overtime or hazard pay awaits them back on Earth
Success
Artemis II’s astronauts are on their way home—a six-figure salary but no overtime or hazard pay awaits them back on Earth
By Fortune EditorsApril 7, 2026
2 days ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.